LoganG1K

thanks guys, I am going to let him borrow my 1200w amp and see if it helps any.

My friend and I built a box for his 1998 silverado extended cab. He has 2 15" rlp's and an Orion 1200w amp. The box is a total of 8.461ft^3 with 69.75in^2 of port area and port length of 26 inches. The box is so big it can only be fired up or down. It is currently firing up and my friend is not satisfied with the output of the subs. There is a lot of pressure but not a lot of volume. He would like to stick with the same box. Would changing the tuning from 28 to 35 hz make a big difference? Do you think that facing it downward would make that much of a difference? If so how much space should there be between the box and the floor? Any other ideas besides get a different vehicle? I know in a car or SUV this setup would be louder.